godan verb (-ku)
think through; think thoroughly; think hard
Implies deep, exhaustive thinking until a conclusion is reached. Often used when solving a problem or making a decision after careful consideration.
一晩中考え抜いて、やっと答えが出た。
I thought it through all night and finally found the answer.
この問題を考え抜くに
It takes time to think this problem through thoroughly.